低融性歯科用リューサイト質陶材(ガラスセラミックス)の開発 : 熱膨張係数と透明度の安定性  [in Japanese] Development of Low-fusing Dental Leucite-Porcelain (Glass-Ceramics) : Stabilities of Thermal Expansion Coefficient and Transparency  [in Japanese]

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Abstract

陶材の主な物性である熱膨張係数(13.5×10<sup>-6</sup>℃)および透明度の安定性を,ガラス粉末(組成:SiO<sub>2</sub> 64.1, Al<sub>2</sub>O<sub>3</sub> 15.0, K<sub>2</sub>O 10.3, Na<sub>2</sub>O 8.5, MgO 0.3, CaO 1.2, B<sub>2</sub>O<sub>3</sub> 0.6wt%)の熱処理(850℃)に伴うリューサイトの生成とそのサニディンヘの転移挙動について研究し,以下の結果を得た.1.陶材中のリューサイトは準安定相で,誘導期間(約10時間)を経てサニディン(安定相)へ転移した.2.陶材の熱膨張係数および透明性は,リューサイトからサニディンヘの転移量の増大に伴って大きく減少した.3.合成リューサイト粉末(1wt%)を混合したガラス粉末で調製した陶材は,その熱膨張係数と透明性が4時間までの熱処理(850℃)によって変化しなかった.即ち,市販陶材(800〜950℃では1時間以内にリューサイトはサニディンへ転移開始)と比較して技工作業での安定性を約4倍に改善できた.

The stabilities of thermal expansion coefficient (13.5×10<sup>-6</sup>℃) and transparency of porcelain, which are main properties, have been investigated concerning in the formations of leucite and the change of leucite to sanidine by the heat-treatment (at 850℃) of the glass powder (SiO<sub>2</sub> 64.1, Al<sub>2</sub>O<sub>3</sub> 15.0, K<sub>2</sub>O 10.3, Na<sub>2</sub>O 8.5, MgO 0.3, CaO 1.2, B<sub>2</sub>O<sub>3</sub> 0.6 wt%). Detailed study show that: 1. After an induction period of about 10 hours under a metastable phase, the leucite in porcelain was changed to sanidine in a stable phase. 2. The thermal expansion coefficient and transparency of porcelain drastically decreased with an increase in the amount of sanidine changed from the leucite. 3. Porcelain prepared in the mixing method of 1wt% synthetic leucite crystal powder showed no change in the thermal expansion coefficient and transparency up to 4 hours at 850℃. This makes its stability improved 4 times as much as major commercial porcelains (in which sanidine is produced in 1 hour at 800 to 950℃).

Journal

  • The Journal of the Japanese Society for Dental Materials and Devices

    The Journal of the Japanese Society for Dental Materials and Devices 25(6), 479-487, 2006

    The Japanese Society for Dental Materials and Devices

References:  31

Cited by:  4

Codes

  • NII Article ID (NAID)
    110004837901
  • NII NACSIS-CAT ID (NCID)
    AN00127279
  • Text Lang
    JPN
  • Article Type
    Journal Article
  • ISSN
    0286-5858
  • Data Source
    CJP  CJPref  NII-ELS  J-STAGE 
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